Furuno FCV-30 - Manual (Page 85)

3. CHANGING SETTINGS
3-17
3.9.4 Setting menu
1. Click Setting on the echo sounder window’s menu bar.
2. Click Echo image.
Range: Choose display range among eight ranges. Display range is automatically chosen
when the Auto mode (Fishing or Cruising) is active.
Shift: Set amount of display range shift.
Gain: Set gain. Gain is automatically chosen when the Auto mode (Fishing or Cruising) is
active.
TVG level: Compensate for propagation attenuation of the ultrasonic waves. It does this by
equalizing echo presentation so that fish schools of the same size appear in the same
density in both shallow and deep waters. The higher the figure, the lower the gain on near
range.
TVG distance: Set effective range of TVG.
Bottom level: If the depth indication is unstable in automatic or manual gain adjustment,
adjust bottom level to get stable depth indication.